This application claims priority from and incorporates by reference the subject matter of Swiss Patent Application No. 2001 1314/01 filed on Jul. 16, 2001.
The invention relates to a securing and arming device having an operating body and a delay element. The invention further relates to the use of such a securing and arming device in connection with a spin-stabilized projectile.
Securing and arming devices of this kind are used to inhibit a function of a mechanism during a mounted or rest state, or prior to a ready or arming time, and in this way to secure the mechanism in its mounted or rest state, and to make possible the function, which had been inhibited up to that time, after the ready or arming time has been reached; this does not mean that the said function takes place immediately before the arming time, but only that, starting at this arming time, this function can be triggered if appropriate triggering measures are being taken. The device therefore is in a standby status after the arming time. Securing and arming devices of this type can be employed, inter alia, in projectiles with mechanical and electronic fuses for inhibiting the fuse function, or the disaggregation of the projectiles up to a defined time. Although the identification of the device as a securing and arming device comes from projectile technology, within the scope of the invention it should not be understood to mean that the device can only be utilized in projectile technology. Devices of this type can moreover be used as securing and arming devices; when reaching the moment which had been called arming time above, the function which was inhibited up to that time becomes active; in this case this is not only made possible, but no further steps need to be taken for the actual performance of this function.
conventional securing and arming devices are basically designed in the form of clockwork mechanisms. They comprise a multitude of structural elements, inter alia rotating parts, in particular gear wheels, a balance wheel, as well as a spring mechanism, if required. The rotating parts are centrally guided, i.e. through their shafts, and some are also driven. Often many structural elements are embodied as stamped parts.
Such securing and arming devices in the form of clockwork mechanisms have many disadvantages, the most serious of which will be briefly described in what follows. Clockwork mechanisms are elaborate as a result of the multitude of the components from which they are constructed, expensive to produce and to assemble. Many components are stamped parts, which often contain inaccuracies and as a result of the stamping process have interfering burs, whose complete removal is time-consuming and difficult, if not impossible. Anyway, precise functioning is only assured if the shafts which guide the rotating parts are exactly lined up with each other, which again increases the production and assembly outlay.
The object of the invention is therefore seen to be
the creation of a securing and arming device of the type mentioned at the outset, by means of which the above described disadvantages of the prior art are avoided, and
the proposal of a preferred utilization of such a securing and arming device.
This object is attained in accordance with the invention in connection with
the securing and arming device having an operating body and a delay element arrayed one inside the other with a ring-like gap and a motion transfer body between the operating body and the element. The object of the invention also includes a spin-stabilized projectile in which the securing and arming device is utilized.
Preferred further developments of the securing and arming device in accordance with the invention are described below.
The securing and arming device in accordance with the invention, only called the device for short in what follows, has an operating body which, by a rotary movement, is moved out of its mounted position into an operating position, which can also be called the standby position. In the mounted position the operating body is secured, or blocked, by means of a securing device, or by at least one securing element. To this end, the securing device is in its securing position. As soon as the securing device is moved out of its securing position into a release position, it releases the operating body and the latter moves out of its mounted position into its operating position. To delay the rotary movement performed in the course of this, i.e. to extend the time interval between leaving the mounted position and reaching the operating position, a delay element is provided, which is put into motion simultaneously with the operating body. The delay element and the operating body are designed as cylindrical, or hollow-cylindrical elements, or wheels with parallel axes, wherein the one wheel axis can be displaced in relation to the other wheel axis parallel with the axis direction. The wheels are designed as an outer wheel and an inner wheel, wherein the inner wheel is arranged inside the outer wheel. Because of this, a gap similar to an arc of a circle is created between facing surfaces of the wheels, which has a gap width which changes positionally and chronologically, which will be explained further down below. As mentioned, the wheels have surfaces which are located facing each other and are essentially cylindrical; but at least one of these surfaces is provided with waves, i.e. it is embodied to be wavy, wherein wave crests and wave troughs extend at least approximately in the direction of the wheel axes. Motion transfer bodies are arranged between the facing surfaces of the wheels, which are in contact with these surfaces and which can be displaced radially, or transversely in respect to the wheel axes. When the wheel which is embodied to be wavy performs a rotary movement, its wave crests and wave troughs move past the motion transfer bodies. The result of this is that the motion transfer bodies are alternately displaced back and forth in a radial direction, so that the other wheel is inevitably caused to perform a tumbling movement. This tumbling movement causes the desired delay effect. The wheels only have geometric axes of rotation, but no physical wheel shafts on which they are arranged; the drive is performed via the circumference; i.e. the wheels are free of wheel shafts.
The following advantages in particular are achieved by means of a device embodied in this way:
The device is designed in such a way that it has no rotating elements which are guided and driven by shafts, i.e. centrally. All components which perform rotating movements are without shafts, i.e. they are guided peripherally, namely at their circumference. Optimal precision with greatly reduced production and assembly outlay is achieved by means of this.
The number of components employed is considerably reduced;
production and assembly are simplified by this.
Practically only molded or extruded plastic parts are used in place of stamped metal parts, so that the problem of production-related burs is prevented.
In preferred exemplary embodiments of the device of the invention, the inner wheel constitutes the operating body and the outer wheel the delay element, and it is preferably the operating body which is embodied to be wavy on its surface which lies facing the delay element.
The operating body has an unbalanced mass, or an eccentrically arranged inertia mass, and is arranged on a support device. The support device rotates around a support device axis which is oriented at least approximately parallel in relation to the axis of rotation of the operating body; it is pointed out that this axis of rotation is merely a geometric, or one-dimensional axis, and not a three-dimensional physical drive or guide shaft. This axis of rotation of the operating body, which is also called a blocking axis or eccentric axis, is arranged eccentrically in relation to the support device axis. In its mounted position the operating body is secured on the support device by the securing device. In the course of this it moves together with the support device, but not relative to the support device. When the securing device gets into its release position, the operating body is released and now can move relative to the support device, or perform a rotary movement around the blocking axis. In the course of this the operating bodyxe2x80x94under the influence of the inertia or centrifugal force acting on itxe2x80x94tries to move into an end position, in which its inertial mass is at the greatest possible distance from the axis of rotation of the support device. This end position corresponds to the operating position, or the standby position.
The displacement of the securing device out of its securing position into its release position preferably also takes place by means of the effect of an inertial force, which acts on the securing device in the radial and/or axial direction during a movement of the support device.
In most cases it has been shown to be advantageous to use a securing device with two separate securing elements; in some applications the arrangement of two securing elements is even prescribed by safety regulations. It is advantageous here to embody a first securing element in the form of a transverse securing bolt, which is arranged in the support device and is pressed into its securing position by the force of a radially oriented spring, i.e. against one of the wheels, preferably the triggering body which is arranged as the outer wheel. By means of this the wheel is secured at the support device, or is blocked, when the support device does not rotate or rotates only slowly. With an increasing speed of rotation of the support device, starting at a defined time, the centrifugal force acting on the transverse securing bolt overcomes the force of the spring. The result of this is that under the influence of the centrifugal force the transverse securing bolt is moved outward into its release position and in the process releases the wheel it had previously acted upon. A second securing element, which is embodied as a linear securing bolt, is provided in addition to the just described first securing element.
In its securing position, the linear securing bolt secures one of the wheels, preferably the operating body, on the support device, as long as the latter is not subjected to any, or not a large linear acceleration in the direction of the support device axis. Then, if the support device is subjected to a linear acceleration of sufficient strength, the linear securing bolt is displaced by the effects of inertia forces into its release position, in which it no longer secures the blocking body on the support device. In principle, each one of the just described securing elements can be employed by itself, i.e. as the sole securing element.
The linear securing bolt is preferably arranged in a recess of the operating body and, in its securing position, one end of it projecting from the operating body engages a complementary recess of the support device. The other end of the linear securing bolt is prevented from sliding out of the recess by means of a retaining element. During a linear, or axial acceleration of the support device, the linear securing bolt, because of the inertial force acting on it, exerts a deforming effect on the retaining element in such a way that the deformed retaining element no longer prevents the linear securing bolt from being displaced.
The retaining element preferably is embodied in such a way that in its deformed configuration it prevents a retrograde movement of the linear securing bolt, by means of which it would be returned into its original position relative to the other components of the device.
To obtain a space-saving arrangement, the placement of the linear securing bolt is advantageously selected in such a way that the total dimension of the device following the displacement of the linear securing bolt is not greater than prior to this displacement.
The linear securing bolt can be received in a hollow body, preferably a hollow cylinder, which in turn is located in the recess of the operating body; in this case the hollow cylinder can constitute the inertial mass, so that a particularly simple device is obtained.
The motion transfer bodies which are contacted by both wheels, i.e. the operating body as well as the delay element, are generally arranged on, or in the support device in such a way that they can be displaced relative to the support device only in the direction of their connection line with the center of the one wheel, preferably the operating body, but are secured against displacement in the direction of the support device axis and in the circumferential direction. But a certain amount of play in the axial direction can be advantageous.
The motion transfer bodies are preferably embodied as rotational solids. Spheres, barrel-like rotational solids, cylinders or truncated cones are advantageous, whose axes are directed parallel, or nearly parallel, in relation to the axes of the wheels, or cylinders and other prismatic bodies, whose axis are radially oriented in relation to the wheels. The dimensions of the motion transfer bodies are selected to match the configuration of the wave crests and wave troughs.
It has been shown to be advantageous to produce the support device in the form of a housing consisting of a base plate and a cover plate.
It is obvious that the time interval for the rotary movement of the operating body is determined by the dimensions and masses of the various moving components of the device, as well by as their surface or frictional properties, and possibly by the linear acceleration of the support device.
As has been mentioned above, the device in accordance with the invention is preferably employed as a securing and arming device for spin-stabilized projectiles. When used in this way, the support device, or the housing having the support device, is fixedly connected with the casing of the projectile, the speed of rotation corresponds to the velocity of the spin and the linear acceleration corresponds to the forward acceleration of the projectile, which the latter undergoes upon being fired.